Flipping homes is becoming a less common way for investors to make money, at least according to the latest numbers released by RealtyTrac.

RealtyTrac, an online provider of housing data, releassed its first quarter 2014 Home Flipping Report, which shows that 3.7 percent of all U.S. single-family home sales during the quarter were flips. RealtyTrac defines a flip as when a home is purchased and then sold again within six months.

Flipping was down from the fourth quarter of 2013 when 4.1 percent of single-family home sales were flips. In the first quarter of 2013, 6.5 percent of all home sales were classified as flips.

How much money were these flippers making? RealtyTrac determined that the average sales price of flipped homes in the first quarter was $55,574 higher than the average original purchase price. Of course, flippers spend plenty of dollars on renovating their homes before selling them again. Taking this into account, RealtyTrac said that flippers took home an unadjusted return on investment of 30 percent of the average original purchase price on the properties they flipped during the first quarter of this year.

That’s actually better than a year ago, when flippers took home an unadjusted rate of return of 28 percent of the average original purchase price of their flipped residences.

“Investors appear to have recalibrated their flipping strategy, accounting for the slower home price appreciation even if that means fewer flips,” said Daren Blomquist, vice president at RealtyTrac. “This is another good sign that the housing recovery is behaving more rationally than the last housing boom, which was built largely on unfounded speculation rather than fact-based calculations.”

It took investors an average of 101 days to complete a flip in the first quarter. That’s up from an average of 92 days in the fourth quarter of 2013 and an average of 79 days for flips completed in the first quarter of 2013.